The reaction between hydroxide ion, $$OH^{-}$$ and phosphinate ions, $$H_{2}PO_{2}^{2-}$$

$$H_{2}PO_2^- (aq) + OH^{-}(aq) \rightarrow H_{2}(g) + HPO_{3}^{2-}(aq)$$

has been studied by following the initial rate of formation of the gaseous product. The results are tabulated below:

What is the overall reaction order?

A

1

B

2

C

3

D

4